package com.yqg.protection.utils;

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

import javax.servlet.http.HttpServletRequest;

/**
 * IP地址
 */
@Component
@Slf4j
public class IPUtils {
    /**
     * 获取IP地址
     *
     * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
     * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ip = null;
        if (request != null) {
            try {
                ip = request.getHeader("x-forwarded-for");
                if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                    ip = request.getHeader("Proxy-Client-IP");
                }
                if (StringUtils.isEmpty(ip) || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                    ip = request.getHeader("WL-Proxy-Client-IP");
                }
                if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                    ip = request.getHeader("HTTP_CLIENT_IP");
                }
                if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                    ip = request.getHeader("HTTP_X_FORWARDED_FOR");
                }
                if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                    ip = request.getRemoteAddr();
                }
            } catch (Exception e) {
                log.error("IPUtils ERROR ", e);
            }
            // 如果有多个IP使用逗号分隔
            if (ip != null && ip.length() > 0) {
                String[] ipArray = ip.split(",");
                // X-Forwarded-For的第一个IP作为真实IP地址
                ip = ipArray[0];
            }
        }
        return ip;
    }
}
